Commercial alkaline chemical relaxers for straightening naturally wavy and curly hair, sometimes called “textured hair,” under strongly alkaline conditions (pH≥12) generally use either an alkali metal hydroxide, or a strong organic base as the active ingredient. Conventional alkali metal hydroxide containing relaxers typically contain sodium hydroxide as the active alkali and are commonly called “lye-type” relaxers. Conventional organic base containing relaxers typically contain guanidine hydroxide as the active alkali and are commonly called “no-lye-type” relaxers. Sodium hydroxide and guanidine hydroxide are generally preferred for effectively achieving a desirable level of straightening under strongly alkaline conditions.
A drawback of a sodium hydroxide, lye-type relaxer is its higher potential for irritation of the scalp during the hair straightening process as compared to a guanidine hydroxide, no-lye type relaxer. An advantage of a sodium hydroxide, lye-type relaxer is that it is a single component system, i.e., the active alkali is an ingredient in the composition and is ready to use. Guanidine hydroxide has a relatively short stability in solution, so a guanidine hydroxide, no-lye type relaxer is a two-component system comprising a cream base and a liquid “activator” that must be mixed together to form guanidine hydroxide in situ. The ingredients of the cream base component are primarily oils, such as petrolatum/mineral oil, emulsifiers, and calcium hydroxide. The liquid activator generally is a solution of guanidine carbonate in water. For use, the cream and liquid activator are mixed together typically at a ratio of about 3.75 to 1 and the freshly made mixture is applied substantially immediately to the curly hair.
A drawback of commercial hair relaxers containing either sodium hydroxide or guanidine hydroxide as the active alkali is that a loss of fiber elasticity can result generally reducing the elasticity of wet fibers by about 35 to about 60 percent, typically at least about 50 percent. Loss of wet fiber elasticity is undesirable and is believed to manifest itself as fiber breakage when the fiber is dry, especially on combing.
There is a need and desire for an alkaline hair relaxer system that substantially conserves fiber elasticity and ameliorates loss of fiber elasticity during the hair relaxing process under strongly alkaline conditions (pH≥12).